package org.apache.maven.artifact.versioning;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.StringTokenizer;

/**
 * Default implementation of artifact versioning.
 *
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 */
public class DefaultArtifactVersion implements ArtifactVersion {
  private Integer majorVersion;

  private Integer minorVersion;

  private Integer incrementalVersion;

  private Integer buildNumber;

  private String qualifier;

  private ComparableVersion comparable;

  public DefaultArtifactVersion(String version) {
    parseVersion(version);
  }

  @Override
  public int hashCode() {
    return 11 + comparable.hashCode();
  }

  @Override
  public boolean equals(Object other) {
    if (this == other) {
      return true;
    }

    if (!(other instanceof ArtifactVersion)) {
      return false;
    }

    return compareTo((ArtifactVersion) other) == 0;
  }

  public int compareTo(ArtifactVersion otherVersion) {
    if (otherVersion instanceof DefaultArtifactVersion) {
      return this.comparable.compareTo(((DefaultArtifactVersion) otherVersion).comparable);
    } else {
      return compareTo(new DefaultArtifactVersion(otherVersion.toString()));
    }
  }

  public int getMajorVersion() {
    return majorVersion != null ? majorVersion : 0;
  }

  public int getMinorVersion() {
    return minorVersion != null ? minorVersion : 0;
  }

  public int getIncrementalVersion() {
    return incrementalVersion != null ? incrementalVersion : 0;
  }

  public int getBuildNumber() {
    return buildNumber != null ? buildNumber : 0;
  }

  public String getQualifier() {
    return qualifier;
  }

  public final void parseVersion(String version) {
    comparable = new ComparableVersion(version);

    int index = version.indexOf("-");

    String part1;
    String part2 = null;

    if (index < 0) {
      part1 = version;
    } else {
      part1 = version.substring(0, index);
      part2 = version.substring(index + 1);
    }

    if (part2 != null) {
      try {
        if ((part2.length() == 1) || !part2.startsWith("0")) {
          buildNumber = Integer.valueOf(part2);
        } else {
          qualifier = part2;
        }
      } catch (NumberFormatException e) {
        qualifier = part2;
      }
    }

    if ((!part1.contains(".")) && !part1.startsWith("0")) {
      try {
        majorVersion = Integer.valueOf(part1);
      } catch (NumberFormatException e) {
        // qualifier is the whole version, including "-"
        qualifier = version;
        buildNumber = null;
      }
    } else {
      boolean fallback = false;

      StringTokenizer tok = new StringTokenizer(part1, ".");
      try {
        majorVersion = getNextIntegerToken(tok);
        if (tok.hasMoreTokens()) {
          minorVersion = getNextIntegerToken(tok);
        }
        if (tok.hasMoreTokens()) {
          incrementalVersion = getNextIntegerToken(tok);
        }
        if (tok.hasMoreTokens()) {
          fallback = true;
        }

        // string tokenzier won't detect these and ignores them
        if (part1.contains("..") || part1.startsWith(".") || part1.endsWith(".")) {
          fallback = true;
        }
      } catch (NumberFormatException e) {
        fallback = true;
      }

      if (fallback) {
        // qualifier is the whole version, including "-"
        qualifier = version;
        majorVersion = null;
        minorVersion = null;
        incrementalVersion = null;
        buildNumber = null;
      }
    }
  }

  private static Integer getNextIntegerToken(StringTokenizer tok) {
    String s = tok.nextToken();
    if ((s.length() > 1) && s.startsWith("0")) {
      throw new NumberFormatException("Number part has a leading 0: '" + s + "'");
    }
    return Integer.valueOf(s);
  }

  @Override
  public String toString() {
    StringBuilder buf = new StringBuilder();
    if (majorVersion != null) {
      buf.append(majorVersion);
    }
    if (minorVersion != null) {
      buf.append(".");
      buf.append(minorVersion);
    }
    if (incrementalVersion != null) {
      buf.append(".");
      buf.append(incrementalVersion);
    }
    if (buildNumber != null) {
      buf.append("-");
      buf.append(buildNumber);
    } else if (qualifier != null) {
      if (buf.length() > 0) {
        buf.append("-");
      }
      buf.append(qualifier);
    }
    return buf.toString();
  }
}
